<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* .red {
            width: 200px;
            background-color: red;
            align-content: center;
        }

        .font35 {
            font-size: 35px;

        } */
        .box {
            width: 100px;
            height: 100px;
            font-size: 30px;
        }

        .red {
            background-color: red;
        }

        .green {
            background-color: green;
        }
    </style>
</head>

<body>
    <!-- <div class="red font35">刘德华</div> -->
    <div class="box red">红色</div>
    <div class="box green">绿色 </div>
</body>

</html>